Well screen



y 1938; G. w. DARST' 2,118,171

WELL SCREEN Filed Nov. 24, 1936 11M In 1 1 ylllfisgmwl 2/ I 17 T012 5 /V1/ {v 2 11 WQM A TTOFP/VE/ Patented May 24, 1938 UNITED STATES Ei i'i'FFIQE WELL SCREEN George W. Darst, San Jose, Calif.

Application November 24, 1936, Serial No. 112,521

1 Claim. (01. 166--5) The present invention relates particularly toReferring now more particularly to the drawthat type of screens used indeep well centrifugal ing, I show at i and 2 the inner and outer tubespump installations, and for drainage purposes. of the screen, onefitting snugly within the other In the manufacture of well screens,where both as clearly shown in Figure 2.

5 economy and efliciency are highly important fac- In the outer tube 2are punched any required 6 tors, it has been somewhat common practice tonumber or arrangement of holes as indicated at 3, build the screen oftwo thicknesses of sheet metal. these holes being clean cut to leave thetube This construction not only provides an extremely smooth on both theinterior and exterior surface. low-priced screen, but also one that isstrong and In the inner tube I are punched slots as 4. Each 1 difiicultto deform. In making this screen several slot 4 is disposedlongitudinally of the tube and 10 different methods of perforating havebeen fclpunched outwardly from the. interior of the tube lowed, chief ofwhich are the following. in such a manner, as with a chisel, to formlips In one method of perforating, both the inner as 5 lying within theconfines oi the hole 3, and and outer tubes are perforated and thenasnot projecting beyond the general outer surface sembled with theperforations registering. One of the outer tube. In forming the cuts 4in this 5 of the principal objections to this method is that mannerinner pockets as 5 are formed, these while the perforations may registerperfectly when pockets having the advantages hereinafter set the twotubes are assembled, the rough handling forth.

of installation may move one tube relative to the A screen constructedin the manner described 21) other in such a manner as to partially oreven cannot be rendered useless, or even partially so, wholly ofiset theperforations, and consequently by shifting of one tube relative to theother bedestroy or limit the efficiency of the screen. cause theoutwardly projecting lips 5 effectually In another method theperforations in the outer prevent such movement, and the screen may betube are made by punching outwardly with a readily'adjusted in a wellbecause of its smooth 25 chisel thereby forming a slitted boss on theout exterior surface. 25

side which interferes with the positioning of the In this form of screenthere are no protuberscreen. Furthermore, by this method pockets areances or bulges on the exterior against which sand formed between theouter slits and the inner tube, can lodge and build up, but rather themovement and these pockets are prone to fill with sand and of both waterand sand is rendered smooth and close off the flow of water. easy. Thisis due largely to the inwardly diverg- 0 It is, therefore, the object ofmy invention to ing walls of the lips 5 forming the flaring pocketsprovide a well screen of the type indicated that 6, whereby any materialpassing through theslots will not only be economical to manufacture,rigid, 4 passes away quickly and easily. strong, and hi hly efficient inits practical pp It is to be understood, of course, that while I cation,but also one that will not pack and close have shown the preferred formof my invention 35 with sand, wherein the flow of water can not be.various changes may be made without departing shut off throughdisplacement of one tube relafrom the spirit of the invention.

tive to the other, and wherein the screen will I (31mm; present a smoothexterior surface with obvious A well screen comprising, a tubular memberadvantageous results. having slots disposed longitudinally thereof and40 Othe Obj c and advantages W appe in punched outwardly from its innerside to form the following descripti n a d 111 the p ybosses on itsouter surface, and a second tubular ing drawing, in which; memberoverlying and encompassing the first Figure 1 is a Side elevation of aportion of a well member having orifices formed therein enscreenembodying my invention. compassing said bosses. 45

Figure 2 is an enlarged section on line 2-2 of Figure 1. GEORGE W.DARSI.

